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Panda Core is the core module of Panda Framework, it contains commonly used utility classes similar to apache-commons.
package panda.doc.markdown;
import panda.doc.html.HTML;
/**
* Utilities.
*/
class Utils {
/** Random number generator value. */
private static int RND = (int)System.nanoTime();
/**
* LCG random number generator.
*
* @return A pseudo random number between 0 and 1023
*/
public final static int rnd() {
return (RND = RND * 1664525 + 1013904223) >>> 22;
}
/**
* Skips spaces in the given String.
*
* @param in Input String.
* @param start Starting position.
* @return The new position or -1 if EOL has been reached.
*/
public final static int skipSpaces(final String in, final int start) {
int pos = start;
while (pos < in.length() && (in.charAt(pos) == ' ' || in.charAt(pos) == '\n'))
pos++;
return pos < in.length() ? pos : -1;
}
/**
* Processed the given escape sequence.
*
* @param out The StringBuilder to write to.
* @param ch The character.
* @param pos Current parsing position.
* @return The new position.
*/
public final static int escape(final StringBuilder out, final char ch, final int pos) {
switch (ch) {
case '\\':
case '[':
case ']':
case '(':
case ')':
case '{':
case '}':
case '#':
case '"':
case '\'':
case '.':
case '>':
case '<':
case '*':
case '+':
case '-':
case '_':
case '!':
case '`':
case '^':
out.append(ch);
return pos + 1;
default:
out.append('\\');
return pos;
}
}
/**
* Reads characters until any 'end' character is encountered.
*
* @param out The StringBuilder to write to.
* @param in The Input String.
* @param start Starting position.
* @param end End characters.
* @return The new position or -1 if no 'end' char was found.
*/
public final static int readUntil(final StringBuilder out, final String in, final int start, final char... end) {
int pos = start;
while (pos < in.length()) {
final char ch = in.charAt(pos);
if (ch == '\\' && pos + 1 < in.length()) {
pos = escape(out, in.charAt(pos + 1), pos);
}
else {
boolean endReached = false;
for (int n = 0; n < end.length; n++) {
if (ch == end[n]) {
endReached = true;
break;
}
}
if (endReached)
break;
out.append(ch);
}
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Reads characters until the 'end' character is encountered.
*
* @param out The StringBuilder to write to.
* @param in The Input String.
* @param start Starting position.
* @param end End characters.
* @return The new position or -1 if no 'end' char was found.
*/
public final static int readUntil(final StringBuilder out, final String in, final int start, final char end) {
int pos = start;
while (pos < in.length()) {
final char ch = in.charAt(pos);
if (ch == '\\' && pos + 1 < in.length()) {
pos = escape(out, in.charAt(pos + 1), pos);
}
else {
if (ch == end)
break;
out.append(ch);
}
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Reads a markdown link.
*
* @param out The StringBuilder to write to.
* @param in Input String.
* @param start Starting position.
* @return The new position or -1 if this is no valid markdown link.
*/
public final static int readMdLink(final StringBuilder out, final String in, final int start) {
int pos = start;
int counter = 1;
while (pos < in.length()) {
final char ch = in.charAt(pos);
if (ch == '\\' && pos + 1 < in.length()) {
pos = escape(out, in.charAt(pos + 1), pos);
}
else {
boolean endReached = false;
switch (ch) {
case '(':
counter++;
break;
case ' ':
if (counter == 1)
endReached = true;
break;
case ')':
counter--;
if (counter == 0)
endReached = true;
break;
}
if (endReached)
break;
out.append(ch);
}
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Reads a markdown link ID.
*
* @param out The StringBuilder to write to.
* @param in Input String.
* @param start Starting position.
* @return The new position or -1 if this is no valid markdown link ID.
*/
public final static int readMdLinkId(final StringBuilder out, final String in, final int start) {
int pos = start;
int counter = 1;
while (pos < in.length()) {
final char ch = in.charAt(pos);
boolean endReached = false;
switch (ch) {
case '\n':
out.append(' ');
break;
case '[':
counter++;
out.append(ch);
break;
case ']':
counter--;
if (counter == 0)
endReached = true;
else
out.append(ch);
break;
default:
out.append(ch);
break;
}
if (endReached)
break;
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Reads characters until any 'end' character is encountered, ignoring escape sequences.
*
* @param out The StringBuilder to write to.
* @param in The Input String.
* @param start Starting position.
* @param end End characters.
* @return The new position or -1 if no 'end' char was found.
*/
public final static int readRawUntil(final StringBuilder out, final String in, final int start, final char... end) {
int pos = start;
while (pos < in.length()) {
final char ch = in.charAt(pos);
boolean endReached = false;
for (int n = 0; n < end.length; n++) {
if (ch == end[n]) {
endReached = true;
break;
}
}
if (endReached)
break;
out.append(ch);
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Reads characters until the end character is encountered, ignoring escape sequences.
*
* @param out The StringBuilder to write to.
* @param in The Input String.
* @param start Starting position.
* @param end End characters.
* @return The new position or -1 if no 'end' char was found.
*/
public final static int readRawUntil(final StringBuilder out, final String in, final int start, final char end) {
int pos = start;
while (pos < in.length()) {
final char ch = in.charAt(pos);
if (ch == end)
break;
out.append(ch);
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Reads characters until any 'end' character is encountered, ignoring escape sequences.
*
* @param out The StringBuilder to write to.
* @param in The Input String.
* @param start Starting position.
* @param end End characters.
* @return The new position or -1 if no 'end' char was found.
*/
public final static int readXMLUntil(final StringBuilder out, final String in, final int start, final char... end) {
int pos = start;
boolean inString = false;
char stringChar = 0;
while (pos < in.length()) {
final char ch = in.charAt(pos);
if (inString) {
if (ch == '\\') {
out.append(ch);
pos++;
if (pos < in.length()) {
out.append(ch);
pos++;
}
continue;
}
if (ch == stringChar) {
inString = false;
out.append(ch);
pos++;
continue;
}
}
switch (ch) {
case '"':
case '\'':
inString = true;
stringChar = ch;
break;
}
if (!inString) {
boolean endReached = false;
for (int n = 0; n < end.length; n++) {
if (ch == end[n]) {
endReached = true;
break;
}
}
if (endReached)
break;
}
out.append(ch);
pos++;
}
return (pos == in.length()) ? -1 : pos;
}
/**
* Appends the given string encoding special HTML characters.
*
* @param out The StringBuilder to write to.
* @param in Input String.
* @param start Input String starting position.
* @param end Input String end position.
*/
public final static void appendCode(final StringBuilder out, final String in, final int start, final int end) {
for (int i = start; i < end; i++) {
final char c;
switch (c = in.charAt(i)) {
case '&':
out.append("&");
break;
case '<':
out.append("<");
break;
case '>':
out.append(">");
break;
default:
out.append(c);
break;
}
}
}
public final static void appendValue(final StringBuilder out, final String in) {
if (in == null || in.length() <= 0) {
return;
}
appendValue(out, in, 0, in.length());
}
/**
* Appends the given string encoding special HTML characters (used in HTML attribute values).
*
* @param out The StringBuilder to write to.
* @param in Input String.
* @param start Input String starting position.
* @param end Input String end position.
*/
public final static void appendValue(final StringBuilder out, final String in, final int start, final int end) {
for (int i = start; i < end; i++) {
final char c;
switch (c = in.charAt(i)) {
case '&':
out.append("&");
break;
case '<':
out.append("<");
break;
case '>':
out.append(">");
break;
case '"':
out.append(""");
break;
case '\'':
out.append("'");
break;
default:
out.append(c);
break;
}
}
}
/**
* Append the given char as a decimal HTML entity.
*
* @param out The StringBuilder to write to.
* @param value The character.
*/
public final static void appendDecEntity(final StringBuilder out, final char value) {
out.append("&#");
out.append((int)value);
out.append(';');
}
/**
* Append the given char as a hexadecimal HTML entity.
*
* @param out The StringBuilder to write to.
* @param value The character.
*/
public final static void appendHexEntity(final StringBuilder out, final char value) {
out.append("&#x");
out.append(Integer.toHexString(value));
out.append(';');
}
/**
* Appends the given mailto link using obfuscation.
*
* @param out The StringBuilder to write to.
* @param in Input String.
* @param start Input String starting position.
* @param end Input String end position.
*/
public final static void appendMailto(final StringBuilder out, final String in, final int start, final int end) {
for (int i = start; i < end; i++) {
final char c;
final int r = rnd();
switch (c = in.charAt(i)) {
case '&':
case '<':
case '>':
case '"':
case '\'':
case '@':
if (r < 512)
appendDecEntity(out, c);
else
appendHexEntity(out, c);
break;
default:
if (r < 32)
out.append(c);
else if (r < 520)
appendDecEntity(out, c);
else
appendHexEntity(out, c);
break;
}
}
}
/**
* Extracts the tag from an XML element.
*
* @param out The StringBuilder to write to.
* @param in Input StringBuilder.
*/
public final static void getXMLTag(final StringBuilder out, final StringBuilder in) {
int pos = 1;
if (in.charAt(1) == '/')
pos++;
while (Character.isLetterOrDigit(in.charAt(pos))) {
out.append(in.charAt(pos++));
}
}
/**
* Extracts the tag from an XML element.
*
* @param out The StringBuilder to write to.
* @param in Input String.
*/
public final static void getXMLTag(final StringBuilder out, final String in) {
int pos = 1;
if (in.charAt(1) == '/')
pos++;
while (Character.isLetterOrDigit(in.charAt(pos))) {
out.append(in.charAt(pos++));
}
}
/**
* Reads an XML element.
*
* @param out The StringBuilder to write to.
* @param in Input String.
* @param start Starting position.
* @param safeMode Whether to escape unsafe HTML tags or not
* @return The new position or -1 if this is no valid XML element.
*/
public final static int readXML(final StringBuilder out, final String in, final int start, final boolean safeMode) {
int pos;
final boolean isCloseTag;
try {
if (in.charAt(start + 1) == '/') {
isCloseTag = true;
pos = start + 2;
}
else if (in.charAt(start + 1) == '!') {
out.append("');
if (pos == -1)
return -1;
final String tag = temp.toString().trim().toLowerCase();
if (HTML.isUnsafeElement(tag)) {
out.append("<");
if (isCloseTag)
out.append('/');
out.append(temp);
}
}
else {
out.append('<');
if (isCloseTag)
out.append('/');
pos = readRawUntil(out, in, pos, ' ', '/', '>');
}
if (pos == -1)
return -1;
pos = readRawUntil(out, in, pos, '/', '>');
if (in.charAt(pos) == '/') {
if (out.length() < 1 || out.charAt(out.length() - 1) != ' ') {
out.append(' ');
}
out.append('/');
pos = readRawUntil(out, in, pos + 1, '>');
if (pos == -1)
return -1;
}
if (in.charAt(pos) == '>') {
out.append('>');
return pos;
}
}
catch (StringIndexOutOfBoundsException e) {
return -1;
}
return -1;
}
/**
* Removes trailing ` and trims spaces.
*
* @param fenceLine Fenced code block starting line
* @return Rest of the line after trimming and backtick removal
*/
public final static String getMetaFromFence(String fenceLine) {
char f = ' ';
for (int i = 0; i < fenceLine.length(); i++) {
final char c = fenceLine.charAt(i);
if (Character.isWhitespace(c)) {
continue;
}
if (f == ' ') {
f = c;
continue;
}
if (f != c) {
return fenceLine.substring(i).trim();
}
}
return "";
}
}